1. Field of the Invention
This invention relates, broadly speaking, to an arrangement for controlling the pitch and rotational velocity of a propeller and of the engine driving the propeller. More particularly, this invention relates to an arrangement for providing a full feathering, reversible pitch propeller especially adapted for aircraft, and having an automatic constant speed feature. Even more specifically, this invention relates to a simple, foolproof, fail-safe mechanical (as distinguished from hydraulic) arrangement for providing a full feathering, reversible pitch, constant speed aircraft propeller on a solid (i.e., undrilled) engine shaft.
2. Description of the Prior Art
Variable pitch propellers have long been known in the prior art. All of these prior art propellers lack one or more features of the present invention.
U.S. Pat. Nos. 1,693,451 (1928) to McCauley, 1,777,254 (1930) to Connors, 1,801,725 (1931) to Cook, 1,839,895 (1932) to Rossi, 1,887,146 (1932) to Conkling, 2,010,640 (1935) to Michl, 2,054,810 (1936) to Gaba, 2,094,149 (1937) to Gaba, 2,452,444 (1948) to Enerud, 2,510,216 (1950) to Figley, 2,656,971 (1953) to Mader, and 3,000,447 (1961) to Baugher all disclose variable pitch propellers. None provides for automatic constant propeller speed (RPM). Some do not disclose full feathering, and some do not provide for reversing the pitch of the propeller.
U.S. Pat. No. 1,861,150 (1932) to Zipay discloses an adjustable pitch airplane propeller with provision for constant speed operation. However, there is no provision disclosed for full feathering the propeller, nor is there any provision disclosed for reversing the pitch of the propeller.
U.S. Pat. No. 1,914,346 (1933) to Squires discloses a propeller with automatic pitch adjustment. There is no provision disclosed for full feathering the propeller, nor is there any provision disclosed for reversing the pitch of the propeller.
U.S. Pat. Nos. 2,112,965 (1938) to Koster, 2,115,485 (1938) to Dodson, 2,628,684 (1953) to Slatter disclose a constant speed adjustable pitch propeller. However, there is no mention of full feathering the propeller or of reversing the pitch of the propeller.
U.S. Pat. Nos. 3,249,159 (1966) to Biermann, 3,551,069 (1970) to Morris and 3,575,529 (1971) to Biermann disclose a constant speed, adjustable pitch propeller, with provision for full feathering and reversing the pitch of the propeller. However, the systems disclosed are hydraulic and require a drilled engine shaft as part of the hydraulic system piping.